There are numerous uses for an x-ray shielding container, such as medical x-ray machines and industrial vision inspection machines. For example, x-ray detection is used to image dense objects, such as human bones, that are located within the body. Another application of x-ray detection and imaging is in the field of non-destructive electronic device testing. For example, x-ray imaging is used to determine the quality of solder that is used to connect electronic devices and modules to printed circuit boards.
X-ray imaging works by passing electromagnetic energy at wavelengths of approximately 0.1 to 100×10−10 meters (m) through the target that is to be imaged. The x-rays are received by a receiver element, known as an x-ray detector, on which a shadow mask that corresponds to the objects within the target is impressed. Dark shadows correspond to dense regions in the target and light shadows correspond to less dense regions in the target. In this manner, dense objects, such as solder, which contains heavy metals such as lead, can be visually distinguished from less dense regions. This allows the solder joints to be inspected easily.
X-ray radiation is dangerous to living beings and the environment. Therefore, x-ray equipment is typically contained within an x-ray shielding container.
The shielding containers in x-ray applications have typically been built from welded steel frames with plates of lead or sheets of granite attached for shielding. Plate lead shielding is very expensive and the sheets of lead are difficult to attach to an enclosure to form a shielded enclosure. A lead enclosure typically requires steel or other exterior enclosure to protect the lead shielding from damage. Lead is also a highly toxic material, making its use in medical, industrial and commercial settings undesirable. It is also very difficult to seal holes, cracks, joints, seams and other leak points in a lead enclosure.
Although granite is not a toxic material, granite-shielding enclosures suffer many of the same shortcomings as lead shielding enclosures. Granite is also very heavy and difficult to manufacture and work with. As most radiation leakage will occur around seams, joints or holes, granite must be worked with in large sheets for large medical and industrial enclosures. This makes working with and transporting a granite enclosure very difficult due to the weight of the enclosure. Moreover, granite composites typically have poor radiation shielding characteristics.
Accordingly, there exists a need for an environmentally safe, low cost, lightweight radiation shielding enclosure with good radiation shielding properties. In particular, a need exists for a radiation shielding enclosure made of a shielding material other than lead or granite.